The task of absorbing a gas in a liquid is encountered in numerous and diverse fields of technology. The present invention is specifically concerned with those gas-liquid absorption processes which are highly exothermic and wherein it is desired to obtain a high-enthalpy solution of the gas in the solvent or a mixture of such a solution with the gas and at the same time to recuperate for further utilization as much as possible of the heat of absorption generated in the process of the absorption of the gas by the solvent.
Examples of technological fields including gas-liquid absorption processes with the above requirements are, typically, the so-called "dual fluid energy conversion systems" or "absorption engines" employing, e.g. ammonia as the gas (or "working fluid") and water as the solvent (or "carrier fluid"). Among the large number of long-standing proposals for such dual fluid energy conversion systems there should be mentioned, for example, U.S. Pat. Nos. 212,037, 337,371, 427.398, 493,722, 1,957,893 and 3,505,810 and British Patent No. 294,882. Whilst all these publications propose the use of an ammonia solution, with the gaseous ammonia produced in a boiler designed to drive an engine and to be subsequently reabsorbed in an aqueous carrier fluid and recycled to the boiler, in all cases the proposed conditions of operation are either clearly inoperable or indicate a very low thermal efficiency.
Attention should also be directed to the more recent U.S. Pat. Nos. 4,195,485, 4,295,335 and 4,307,572 all to Brinkerhoff who discloses the use of dual fluid systems in energy conversion cycles and directs himself specifically to utilizing internal heat sources in the cycle. To this end he proposes, inter alia, the recovery and use of at least part of the heat of absorption generated in an absorber wherein the working fluid vapour, after having produced work, is absorbed in the carrier fluid. Brinkerhoff, however, same as all the other aforementioned references, does not concern himself with the conditions which must obtain in the absorber and in the fluids which flow therethrough in order to ensure a continuous, efficient absorption of the gas in the liquid and recover as much as possible of the generated heat of absorption.